File-system utilities for installd and zygote. (9685194f) · Commits · e / os / android_system_core

include/cutils/fs.h

0 → 100644

+47 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2012 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#ifndef __CUTILS_FS_H
		#define __CUTILS_FS_H

		#include <sys/types.h>

		#ifdef __cplusplus
		extern "C" {
		#endif

		/*
		* Ensure that directory exists with given mode and owners.
		*/
		extern int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid);

		/*
		* Read single plaintext integer from given file, correctly handling files
		* partially written with fs_write_atomic_int().
		*/
		extern int fs_read_atomic_int(const char* path, int* value);

		/*
		* Write single plaintext integer to given file, creating backup while
		* in progress.
		*/
		extern int fs_write_atomic_int(const char* path, int value);

		#ifdef __cplusplus
		}
		#endif

		#endif /* __CUTILS_FS_H */

include/cutils/multiuser.h

+3 −3

Original line number	Diff line number	Diff line
		@@ -30,9 +30,9 @@ extern "C" {
		typedef uid_t userid_t;
		typedef uid_t appid_t;

		extern userid_t multiuser_getUserId(uid_t uid);
		extern appid_t multiuser_getAppId(uid_t uid);
		extern uid_t multiuser_getUid(userid_t userId, appid_t appId);
		extern userid_t multiuser_get_user_id(uid_t uid);
		extern appid_t multiuser_get_app_id(uid_t uid);
		extern uid_t multiuser_get_uid(userid_t userId, appid_t appId);

		#ifdef __cplusplus
		}

libcutils/Android.mk

+1 −0

Original line number	Diff line number	Diff line
		@@ -75,6 +75,7 @@ ifeq ($(WINDOWS_HOST_ONLY),1)
		else
		commonSources += \
		abort_socket.c \
		fs.c \
		selector.c \
		tztime.c \
		multiuser.c \

libcutils/fs.c

0 → 100644

+138 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2012 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#include <cutils/fs.h>
		#include <cutils/log.h>

		#include <sys/types.h>
		#include <sys/stat.h>
		#include <fcntl.h>
		#include <unistd.h>
		#include <errno.h>
		#include <string.h>
		#include <limits.h>

		#define ALL_PERMS (S_ISUID \| S_ISGID \| S_ISVTX \| S_IRWXU \| S_IRWXG \| S_IRWXO)
		#define BUF_SIZE 64

		int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid) {
		// Check if path needs to be created
		struct stat sb;
		if (lstat(path, &sb) == -1) {
		if (errno == ENOENT) {
		goto create;
		} else {
		ALOGE("Failed to stat(%s): %s", path, strerror(errno));
		return -1;
		}
		}

		// Exists, verify status
		if (!S_ISDIR(sb.st_mode)) {
		ALOGE("Not a directory: %s", path);
		return -1;
		}
		if (((sb.st_mode & ALL_PERMS) == mode) && (sb.st_uid == uid) && (sb.st_gid == gid)) {
		return 0;
		} else {
		goto fixup;
		}

		create:
		if (mkdir(path, mode) == -1) {
		ALOGE("Failed to mkdir(%s): %s", path, strerror(errno));
		return -1;
		}

		fixup:
		if (chmod(path, mode) == -1) {
		ALOGE("Failed to chown(%s, %d): %s", path, mode, strerror(errno));
		return -1;
		}
		if (chown(path, uid, gid) == -1) {
		ALOGE("Failed to chown(%s, %d, %d): %s", path, uid, gid, strerror(errno));
		return -1;
		}

		return 0;
		}

		int fs_read_atomic_int(const char* path, int* out_value) {
		int fd = open(path, O_RDONLY);
		if (fd == -1) {
		ALOGE("Failed to read %s: %s", path, strerror(errno));
		return -1;
		}

		char buf[BUF_SIZE];
		if (read(fd, buf, BUF_SIZE) == -1) {
		ALOGE("Failed to read %s: %s", path, strerror(errno));
		goto fail;
		}
		if (sscanf(buf, "%d", out_value) != 1) {
		ALOGE("Failed to parse %s: %s", path, strerror(errno));
		goto fail;
		}
		close(fd);
		return 0;

		fail:
		close(fd);
		*out_value = -1;
		return -1;
		}

		int fs_write_atomic_int(const char* path, int value) {
		char temp[PATH_MAX];
		if (snprintf(temp, PATH_MAX, "%s.XXXXXX", path) >= PATH_MAX) {
		ALOGE("Path too long");
		return -1;
		}

		int fd = mkstemp(temp);
		if (fd == -1) {
		ALOGE("Failed to open %s: %s", temp, strerror(errno));
		return -1;
		}

		char buf[BUF_SIZE];
		int len = snprintf(buf, BUF_SIZE, "%d", value) + 1;
		if (len > BUF_SIZE) {
		ALOGE("Value %d too large: %s", value, strerror(errno));
		goto fail;
		}
		if (write(fd, buf, len) < len) {
		ALOGE("Failed to write %s: %s", temp, strerror(errno));
		goto fail;
		}
		if (close(fd) == -1) {
		ALOGE("Failed to close %s: %s", temp, strerror(errno));
		goto fail_closed;
		}

		if (rename(temp, path) == -1) {
		ALOGE("Failed to rename %s to %s: %s", temp, path, strerror(errno));
		goto fail_closed;
		}

		return 0;

		fail:
		close(fd);
		fail_closed:
		unlink(temp);
		return -1;
		}

libcutils/multiuser.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -16,14 +16,14 @@

		#include <cutils/multiuser.h>

		userid_t multiuser_getUserId(uid_t uid) {
		userid_t multiuser_get_user_id(uid_t uid) {
		return uid / MULTIUSER_APP_PER_USER_RANGE;
		}

		appid_t multiuser_getAppId(uid_t uid) {
		appid_t multiuser_get_app_id(uid_t uid) {
		return uid % MULTIUSER_APP_PER_USER_RANGE;
		}

		uid_t multiuser_getUid(userid_t userId, appid_t appId) {
		uid_t multiuser_get_uid(userid_t userId, appid_t appId) {
		return userId * MULTIUSER_APP_PER_USER_RANGE + (appId % MULTIUSER_APP_PER_USER_RANGE);
		}